Locking bolt or fastening device



May 20,v 1941. L. L. HAYNES LOCKING BOLT 0R FASTENING DEVICE Filed June 4, 1940 Wagga-wwwa .Z. [fag/ze@ /7 770/?/1/5 VIS.

Patented May Z0, 1941 LOCKING BLT GR FAiSTENlNG DEVCE "Lionel Leslie Haynes, Bromsgrove, England Applicationdune 4, 1940, Serial No.' 338,78??

".In GreatBritain August 3,1939

rclaim. (ci. eea-144) This invention comprises certain improvements in or relating to locking bolts ,or fastening devices for doors or the like of vthe type in which the locking bolt is projected by uid pressure acting on a piston which pressure may be created by a pump When a vehicle or machine is driven and which pressure may be released when the pump ceases to create pressure.

The invention has for its object a construction of locking bolt device Which is compact and strong and in which liability of same getting out of order is reduced to a minimum. A further object is to construct a locking device of the character above mentioned which Whilst being strong, is compact and can be easily fitted in arecess in a frame. A still further object is to provide for a quick. release of the pressure projecting the locking bolt when such bolt is to be retracted.

In order that the invention may be clearly understood and readily carried into effect reference may be had to the accompanying drawing which illustrates in side elevation, partly in cross section, a device constructed according to this invention.

According to aconvcnient embodiment of this invention, a piston or plunger I is mounted in a cyiinder 2, the inner end of which is tted With a conduit 3 for oil or other uuid supplied under pressure for moving the piston. The piston carries a central rod 4 on which a locking bolt 5 is siidably engaged. This locking bolt 5 is slidably mounted in an extension 2a of the piston cyilnder 2, and the inner end of the locking bolt has a collar 6 slidabiy mounted in such eXtension, the locking bolt being bored centrally for slidably receiving the end of the said rod 4 on the piston. A spiral spring l surrounds this rod and one end is adapted to bear against the piston l Whilst the other end bears against the collar 5 on the locking bolt. A spiral spring 3 is located around the locking bolt 5 and is adapted to bear on one end against the said'collar 6, Whilst the other end bears against a shoulder on the outer end of the extension cylinder 2a. lVhen there is no fluid pressure, the piston l is pressed back by the spring l bearing thereagainst, Whilst the locking bolt is also pressed back by the spring 8 bearing on the collar on such locking bolt. The relative strength of the springs l and 8, and their lengths When not compressed, are such that the spring 8 holds the bolt in the retracted position When fluid pressure is not applied to the plunger l, and when the fluid pressure is applied, the spring 'l compresses the spring 8 When the spring I is compressed by the-plunger, to project the bolt. The nosef5a `of the locking bolt-is of rectangular sectiomand its movement is limited by a grub screw 9 which engages a longitudinal groove l0 in the bolt. When the oil or other fluid is ksupplied under pressure into the piston chamber, the piston I is moved and the piston spiral spring 'I is also moved therewith, so that such spring projects the locking belt against the pressure of the spring 8 located therearound and this latter spring is compressed.. When the locking bolt is projected into the locking position, it can be depressed by sliding in the cylinder on the pin carried by the piston against the compression of the piston spring l. Thus should the locking bolt be projected before the door or like part is closed or moved into position to be locked, the door or the like can be slammed Vinto the closed position. When the pressure of the fluid on the piston is released, the locking bolt Will be automatically retracted, one spring returning the bolt and the other returning the piston or plunger. When in the retracted position as shown, the piston spring is slightly in compression. The upward movement of the piston may be limited by a shoulder or by the tension of the compressed springs, which at this state permit the locking bolt to be retracted against the pressure of such spring.

The bolt is particularly adapted for use with a pressure creating means as set forth in my copending application for Patent Ser. No. 338,788. When therefore the vehicle or machine is started in motion the pump li will deliver oil into the piston chamber and project the locking bolt in the locking position. When the machine or the vehicle is stopped the uid pressure is automatin cally released and the bolt is retracted.v

A number of locking bolts as aforedescribed can be actuated from a single pump or single source of pressure, so that, for instance, all the doors of a railway carriage are operated from the same pressure source.

The pump Il is driven through suitable gearing from the driving sprocket l2 which is suitably driven from a machine tool, vehicle or the In lieu of the locking bolt being re- 1 force of the spring I5 and opens the feed conduit to apply pressure to the bolt control piston. When the pump II ceases to be driven, the pressure in the pressure cylinder I3 drops and the piston I4 returns to the end of the cylinder. An annular groove I6 is formed in the Piston and when the piston is in this latter position the feed conduit 3 is placed in communication with a discharge conduit I'I, thereby allowing the pressure to be relieved on the piston I controlling the locking bolt 5.

I claim:

A locking mechanism for closures, comprising a cylindrical casing, a piston located at one end and adapted to be moved by fluid pressure, a locking bolt, having a bevelled nose, slidably mounted in the other end of the casing, means for telescopically connecting the piston and boltl by a projection on the one member engaging, with a sliding fit, a recess in the other member, a collar on the inner portion of the bolt, a helical spring which encircles the bolt and bears on the said collar and on an internal shoulder on the casing to normally retract the bolt and a spring encircling a stem on the piston and bearing at one end on the collar and at the other end on the piston, and through the intermediary of which the locking bolt is projected into the locking position and whereby the locking bolt can be retracted by pressure on the bevelled nose, means limiting the outward movement of the bolt and a shoulder on the cylindrical casing limiting the power stroke of the piston.

LIONEL LESLIE HAYNES. 

